Feature:1. Product Material: Made of AL7075 aluminum alloy + ceramic bearing material, ceramic bearing, light weight, high lubrication, durable.2. Tooth Shape: Specially optimized tooth shape, synchronized with the chain drive direction, so that the chain can be disconnected more smoothly.3. Tooth Marks: Deepen tooth marks, clearer gear shifting, more stable windings, providing users a good using experience.4. Product Color: The optional colors are red, blue, gold, black and seven colors, you can choose according to your preferences.5. Applicable Models: Bicycle rear derailleur pulle is suitable for most of the rear derailleur on the market, support 7/8/9/10 speed.Specification:Item Type: 17T Ceramic Rear Derailleur Pulley GuideMaterial: AL7075 Aluminum Alloy + Ceramic BearingWeight: Approx. 18g/0.6ozDiameter: Approx. 68mm/2.7inInstallation Size: Approx. 4/5/6mm / 0.16/0.2/0.24in AxleAdvantages: Applicable to Most Rear Derailleur on the Market, Supporting 7/8/9/10 Speed.Package List:1 x Rear Derailleur Pulley Guide2 x Axle